Nick's is a very popular place at Laguna Beach for brunch and dinner. I wouldn't try it on Valentine's Day, but maybe sometime during your 2 days stay. I went there a few times and they are always busy. I actually like the Wahoo's Fish Taco at Laguna. I know they are everywhere in SoCal, but I like the one at Laguna the most and you don't need a reservation ever LOL.
As for other places at Laguna Beach, we usually only go to the beach there in the summer or go to the Pageant of the Masters which is also in the summer. My brother lives near there and they go to something called the 1000 steps beach every week or 2. I have never been there, but according to him and his wife it is pretty there and they like to walk up and down the steps for exercise. For me, I would rather have a foot massage than walking up and down the steps....